Ni-cad drives

[BobbyR]

All the motor drives I have now use AA batteries, but I see some drives with Ni-cads selling for comparatively low prices (though as usual there seems to be no logic to prices paid) because some thing is wrong with the Ni-cad batteries unit.(never specified what is wrong, but they say probably needs new batteries)

Are these usually easy fixes, or something to avoid like the plague?

Although Lithium batteries make worry about dead batteries less of a problem, it would be nice to have a battery pack that can be plugged-in and charged.

 

[Remi]

Here's why I like AA batteries better:
1. You can use "real" AA (alkaline/lithium) batteries if you need to.
2. You can (usually) use rechargeable NiMH batteries too - they're cheap and the charger is cheap too.

Here's why I don't like Ni-Cad batteries in cameras:
1. They're proprietary - the batteries and the charger cost an arm an a leg. They're also discontinued quickly after the camera is discontinued.
2. You have exactly one NiCad battery - when it's discharged, the camera becomes a nice doorstop.
3. Cadmium is a horrible pollutant.

 

[David A. Goldfarb]

I agree with Remi. I had a Ni-Cd pack for my Canon motor drive, and when it no longer held a charge, I bought a AA pack and sold the Ni-Cd for parts, so someone else could deal with re-celling it. The AA pack is heavier and bulkier (12 batteries), but gets a little more speed and supplies more current. 4.5 vs. 5 fps is no big deal to me, but the slight improvement in lag time and readiness for the next shot is noticable.

 

[srs5694]

I'm not familiar with the design of the motor drives in question, but several possible downsides occur to me:

• The battery will eventually fail. Over time, NiCd batteries lose their ability to hold a charge. If the battery is solidly embedded in the motor drive or is of an obscure type, it might be expensive to replace, so you'd end up with a useless motor drive.
• NiCd is old technology as far as rechargeable batteries go. NiMH is much more popular these days, because NiMH batteries hold more charge and are likely to last longer before failing completely. There are other varieties, too. I don't know what's an optimal rechargeable battery for a camera motor drive, but I'd be shocked if it were NiCd.
• Given equal size, rechargeable batteries won't last as long as alkaline batteries. Being able to recharge them is of course a big plus, but if you need something that'll last a while because you expect to shoot a lot of film before you'll be able to plug in the charger, some form of removable battery is best. (These could be removable AA NiMH batteries, of course, if you've got a spare set or two.)
• It's possible there's something wrong with the specific motor drives you've seen, perhaps even something unrelated to their batteries.

 

[copake_ham]

First off, what I think you are calling "drives" or "motor drives" are battery packs.

I certainly agree that NiCds are old technology and not worth it. They will likely develop a "memory" over time which will firstly prevent them from achieving full charge and over time the charge that they can hold will diminish until they're useless. It is an inherent feature of such batteries that can never be avoided and is easily advanced because most folks tend to "top off" the battery packs after usage rather than letting them fully discharge. It is this "topping off" that creates the "memory" or "plateau" effect.

NiMh's tend to avoid this problem to a greater degree - but also are problematic - espescially since they have a rapid drop off rate once the voltage gets down to around 11 v. M/L at that point they fall off the cliff and drop to near zero voltage. Not a good thing if you're in the middle of a shoot when this happens.

Lithium batteries would be much better - they're the ones in your cell phone - but I'm not aware of any such battery packs made for camera gear (at least for our analog stuff).

As srs5694 suggests, using rechargeable NiMh's in a standard battery pack might be a good way to go - so long as you keep a set of regular AA's in your pocket if/when the NiMh's "fall off the voltage cliff".

 

[PhotoJim]

Everyone is giving good advice, but there is one major advantage of NiCd batteries over NiMH and alkaline cells: their extreme cold-weather performance is better than the alternatives.

Environmentally they are bad (although they are fully recyclable, which mitigates this), but they are not a lot worse than NiMH batteries. The sheer popularity of NiMH these days means that the environmental damage caused by NiMH batteries greatly exceeds that of NiCd.

On the whole, though, I prefer using AAs where I can. Most of my 35mm cameras use AAs and all of my motor drives do.